Study underlines cell phone driving danger

Listening on a cell phone, even with a headset and free hands, can make a driver as dangerous as a drunken one, a new study suggests.

Researchers have previously explored this territory, but Carnegie Mellon University scientists tried a new tack: they looked at the brain.

They used brain imaging to show that listening to a cell phone significantly reduces the brain activity that occurs during undistracted driving. This drop in brain function increases driving mistakes &#8212; such as weaving out of the lane or hitting a berm on the shoulder of the road.

&quot;So how big a deal is this?&quot; said lead author Marcel Just, a neuroscientist and director of Carnegie Mellon's Center for Cognitive Brain Imaging. &quot;If you're on a cell phone, it's just an added risk. I certainly don't want to be crossing the road while you're driving and talking on a cell phone.&quot;

A cell phone industry official said he could not comment on the study itself, having not seen it, but that it makes sense to reduce distractions while driving, whether it's dialing a number or putting on makeup.

In the study, to be published in the journal Brain Research, 29 drivers 18 to 25 used a driving simulator while inside a sophisticated brain scanning machine, called functional MRI. They steered a car along an empty but winding two-lane highway at a fixed speed of 43 miles per hour.

Then, they repeated the simulation while listening to statements of general knowledge. After each statement, they had five seconds to say whether it was true or false.

The MRI measured second-by-second changes in activity in 20,000 brain locations. It showed that listening caused a 37 percent decrease in activity in the parietal lobe, which controls skills involved in driving. Activity also decreased in the occipital lobe, the center of visual information processing.

At the same time, listening increased activity in the area of the cortex that is linked to language.

&quot;You know the old TV commercial of an egg frying that said, This is your brain on drugs'?&quot; Just said. &quot;Well, this is your brain on cell phone.&quot;